Tire pressure management system and method of decreasing tire pressure

ABSTRACT

A tire pressure management system includes a wheel valve. The wheel valve is in fluid communication with a wheel assembly. A supply valve assembly is selectively in fluid communication with the wheel valve through a fluid control circuit. The supply valve assembly permits fluid communication between a source of pressurized air and the fluid control circuit. A control valve assembly is selectively in fluid communication with the wheel valve through the fluid control circuit. The control valve assembly permits fluid communication between the source of pressurized air and the fluid control circuit or between the fluid control circuit and atmosphere.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit, under 35 U.S.C. 365, of PCTapplication no. PCT/US2016/029156, which was filed Apr. 25, 2016, andclaims the benefit, under 35 U.S.C. 119(e), of the provisional U.S.patent application which was granted Ser. No. 62/153,183 and filed onApr. 27, 2015, the entire disclosure of which is hereby incorporated byreference.

BACKGROUND OF THE INVENTION

The invention relates to a tire pressure management system. Moreparticularly, the invention relates to a tire pressure management systemand a method of decreasing tire pressure.

Certain types of vehicles such as, for example, commercial vehiclesrequire that the tire pressure of their wheel assemblies be periodicallyadjusted for optimal performance. Tire pressure management systems suchas, for example, central tire inflation systems can be utilized tomanually and/or automatically adjust the pressure within one or morewheel assemblies. Typically, in order to determine when an adjustment isnecessary and to avoid overinflation or underinflation, the tirepressure is measured. If, after measuring the tire pressure, it isdetermined that the tire pressure of a particular tire needs to bedecreased, then the tire pressure management system enables the tirepressure decrease.

Current tire pressure management systems capable of decreasing tirepressure are limited by cost, complexity and the rate at which the tirepressure can be decreased. Therefore, it would be desirable to provide asystem and method which are less expensive and less complex than thoseknown and that can decrease the tire pressure quickly.

BRIEF SUMMARY OF THE INVENTION

Embodiments of a tire pressure management system are provided.

In an embodiment, the tire pressure management system comprises a wheelvalve. The wheel valve is in fluid communication with a wheel assembly.A supply valve assembly is selectively in fluid communication with thewheel valve via a fluid control circuit. The supply valve assemblypermits fluid communication between a source of pressurized air and thefluid control circuit. A control valve assembly is selectively in fluidcommunication with the wheel valve via the fluid control circuit. Thecontrol valve assembly permits fluid communication between the source ofpressurized air and the fluid control circuit or between the fluidcontrol circuit and atmosphere.

Embodiments of a method for decreasing tire pressure are provided.

In an embodiment, the method for decreasing tire pressure comprisesproviding a wheel assembly that houses pressurized air. A wheel valve isprovided. The wheel valve is in fluid communication with the wheelassembly. The wheel valve is operable from an open position to a closedposition. A supply valve assembly is provided. The supply valve assemblyis selectively in fluid communication with the wheel valve via a fluidcontrol circuit. A control valve assembly is provided. The control valveassembly is selectively in fluid communication with the wheel valve viathe fluid control circuit. A deflate member is provided. The deflatemember is in fluid communication with the control valve assembly and isselectively in fluid communication with the wheel valve. A target tirepressure is selected. If a pressure of the pressurized air in the wheelassembly is greater than the target tire pressure, then the pressure ofthe pressurized air in the wheel assembly is decreased by directing aflow of pressurized air from the wheel assembly through the wheel valve,control valve assembly, and deflate member.

BRIEF DESCRIPTION OF THE VIEWS OF THE DRAWING

The above, as well as other advantages of the present invention willbecome readily apparent to those skilled in the art from the followingdetailed description when considered in the light of the accompanyingdrawings in which:

FIG. 1 is a schematic view of an embodiment of a tire pressuremanagement system in accordance with the invention; and

FIG. 2 is a schematic view of another embodiment of a tire pressuremanagement system in accordance with the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

It is to be understood that the invention may assume various alternativeorientations and step sequences, except where expressly specified to thecontrary. It is also to be understood that the specific assemblies,articles and features illustrated in the attached drawings, anddescribed in the following specification are simply exemplaryembodiments of the inventive concepts. Hence, specific dimensions,directions, or other physical characteristics relating to theembodiments disclosed are not to be considered as limiting, unlessexpressly stated otherwise. Also, although they may not be, likeelements found in the aforementioned embodiments may be referred to withlike reference numerals within this section of the application.

A tire pressure management system and a method of decreasing tirepressure are described herein.

Preferably, the tire pressure management system is a central tireinflation system (CTIS). The tire pressure management system is providedon a vehicle (not depicted). A preferred type of vehicle is a commercialvehicle. Commercial vehicles are known in the art. However, the systemand method described herein may also have applications in vehicles forboth light and heavy duty and for passenger and off-highway vehicles.Furthermore, it would be understood by one of ordinary skill in the artthat the system and method could have industrial, locomotive, militaryand aerospace applications. Also, it should be appreciated that thesystem may be utilized and the method may be practiced prior to orduring operation of the vehicle.

The tire pressure management system and method will be described inconnection with a fluid. For the purposes of describing the system andmethod, the fluid will hereinafter be referred to as air. However,alternative fluids are capable of being utilized in the tire pressuremanagement system and in practicing the method.

Embodiments of the tire pressure management system 10, 10A areillustrated in FIGS. 1 and 2. The tire pressure management system may beutilized to maintain, increase and/or decrease the tire pressure of oneor more wheel assemblies. Maintaining, increasing and/or decreasing tirepressure is advantageous as it may improve the fuel economy and increasethe life of the tires of the vehicle.

In certain embodiments, the tire pressure management system 10, 10Acomprises a control unit 12. The control unit 12 is configured to enabledetermining the tire pressure of one or more wheel assemblies and, ifneeded, increasing or decreasing the tire pressure thereof. The controlunit 12 is also configured to enable venting the air from of one or moreportions of the tire pressure management system 10, 10A.

The control unit 12 comprises a housing 14. An electronic controlportion 16 and a pneumatic control portion 18 are provided within thehousing 14.

The electronic control portion 16 may include a microprocessor 24operating under the control of a set of programming instructions, whichmay also be referred to as software. The electronic control portion 16may include a memory (not depicted) in which programming instructionsare stored. The memory can also store identification codes, tirepressure records and/or user inputs over a period of time.

The electronic control portion 16 may receive input signals from apressure sensor 26, power supply 28 and one or more additional sensors(not depicted) such as, for example, a load sensor and a speed sensor.The load sensor and speed sensor may each be conventional in the art.The pressure sensor 26 may also be referred to as a pressure transducerand will be discussed in greater detail below. The electronic controlportion 16 may also receive input signals from an operator controldevice 30.

The operator control device 30 may allow an operator of the vehicle toexert a certain level of control over the tire pressure managementsystem 10, 10A. The operator control device 30 may be conventional inthe art. The operator control device 30 permits an operator of thevehicle to transmit control signals to the electronic control portion 16to adjust the tire pressure.

The electronic control portion 16 outputs signals to one or more membersof the pneumatic control portion 18. Preferably, the electronic controlportion 16 outputs signals to a plurality of valve assemblies 32, 34,36, 38 of the pneumatic control portion 18. The output signals may beelectrical current. Electrical current can be received by a valveassembly 32, 34, 36, 38 to energize the assembly. Similarly, electricalcurrent can be removed from the valve assembly 32, 34, 36, 38 tode-energize the valve assembly. As will be discussed in more detailbelow, energizing and de-energizing a valve assembly 32, 34, 36, 38urges the valve assembly 32, 34, 36, 38 from a first position to asecond position or vice versa. The electronic control portion 16 mayalso output signals to a display device (not depicted). The displaydevice may be included as a part of the operator control device 30 or afreestanding device.

The pneumatic control portion 18 may comprise one or more conduits 40,42, 44 provided within the housing 14 and one or more ports 46, 48formed in the housing 14. In an embodiment, an air supply port 46 isformed in the lower portion 22 of the housing 14. The air supply port 46is in fluid communication with an air supply conduit 40 provided withinthe housing 14. Also, the air supply port 46 is in fluid communicationwith an air supply circuit 50.

The tire pressure management system 10, 10A includes a source ofpressurized air 52. Pressurized air is supplied to control unit 12 fromthe source of pressurized air 52 via the air supply circuit 50.Preferably, the source of pressurized air 52 comprises a reservoir 54such as, for example, a wet tank. Preferably, a compressor 56 isattached to the vehicle and in fluid communication with the wet tank viaa supply conduit 58. The air compressor 56 supplies pressurized air tothe wet tank for storage therein. In certain embodiments, a drier 60 isinterposed in the air supply circuit 50 for removing water from the air.A filter (not depicted) may also be interposed in the air supply circuit50.

The pressurized air may be utilized to determine the tire pressure and,if needed, open one or more wheel valves 62, 62A, 62B, 62C and increasethe tire pressure. The pressurized air provided in the air supplycircuit 50 and supplied from the source of pressurized air 52 comprisesair at a certain pressure. The pressure sensor 26 measures the pressureof the pressurized air provided in the air supply circuit 50. It ispreferred that the pressurized air provided in the air supply circuit 50is at a pressure which is greater than the tire pressure. Preferably,the pressure of the pressurized air provided in the air supply circuit50 is greater than the target tire pressure so that the tire pressurecan, if needed, be increased to the target tire pressure. In anembodiment, the pressure of the air provided in the air supply circuit50 is equal to the target tire pressure plus 5 psig or more.

The air supply conduit 40 is attached to and extends from the air supplyport 46. The air supply conduit 40 is attached to and in fluidcommunication with the control valve assembly 32. Also, the air supplyconduit 40 is attached to and in fluid communication with the supplyvalve assembly 34. Preferably, the control valve assembly 32 and thesupply valve assembly 34 are provided within the housing 14.

In certain embodiments, the control valve assembly 32 and supply valveassembly 34 are of the solenoid variety. Preferably, in theseembodiments, the control valve assembly is of the 3-way variety. In anembodiment, like the one illustrated in FIG. 1, the supply valveassembly 34 is also of the 3-way variety. However, in other embodiments,like the one illustrated in FIG. 2, the supply valve assembly 34 is ofthe two-way variety.

The control valve assembly 32 is operable from a first position througha second position. Also, the supply valve assembly 34 is operable from afirst position through a second position. Preferably, the control valveassembly 32 and the supply valve assembly 34 are both normally in thefirst position. Preferably, when the control valve assembly 32 isde-energized, the valve assembly 32 is in or placed in the firstposition. Preferably, when the supply valve assembly 34 is de-energized,the valve assembly 34 is in or placed in the first position. Preferably,when the control valve assembly 32 is energized, the valve assembly 32is in or placed in the second position. Also, it is preferred that whenthe supply valve assembly 34 is energized, the valve assembly 34 is inor placed in the second position.

The control valve assembly 32 is selectively in fluid communication withone or more wheel valve assemblies 62, 62A, 62B, 62C via one or more ofthe fluid control circuits 64, 66. As illustrated in FIGS. 1 and 2, anorifice 63 is provided in the air supply conduit 40 upstream of thecontrol valve assembly 32. In other embodiments (not depicted), theorifice 63 may be provided downstream of the control valve assembly 32.In one such embodiment, the orifice may be provided downstream of thecontrol valve assembly 32 and in the central fluid conduit 44. Theorifice 63 and the control valve assembly 32 are utilized to communicatea small flow or bleed of pressurized air to the first fluid conduit 42and/or one or more fluid control circuits 64, 66. The control valveassembly 32 may also be utilized to decrease the tire pressure of one ormore wheel assemblies 68, 68A, 68B, 68C.

The supply valve assembly 34 is selectively in fluid communication withone or more wheel valve assemblies 62, 62A, 62B, 62C via one or more ofthe fluid control circuits 64, 66. The supply valve assembly 34 may beutilized to communicate pressurized air to the first fluid conduit 42and/or one or more of the fluid control circuits 64, 66 to determineand/or increase the tire pressure of one or more wheel assemblies 68,68A, 68B, 68C. For example, when the supply valve assembly is energizedand/or in the second position, the supply valve assembly permits fluidcommunication between the source of pressurized air 52 and a fluidcontrol circuit 64, 66. Alternatively, as illustrated by the embodimentdepicted in FIG. 1, the supply valve assembly 34 may be utilized todirect pressurized air from one or more wheel assemblies 68, 68A, 68B,68C to the control valve assembly 32 when the tire pressure of the oneor more wheel assemblies 68, 68A, 68B, 68C is being decreased. In theembodiments illustrated in FIGS. 1 and 2, when the supply valve assembly34 is de-energized and/or in the first position, the supply valveassembly 34 prohibits fluid communication between the source ofpressurized air 52 and a fluid control circuit 64, 66.

When the control valve assembly 32 is energized and/or in the secondposition, the control valve assembly 32 permits fluid communicationbetween the source of pressurized air 52 and one or more fluid controlcircuits 64, 66. In an embodiment, like the one illustrated in FIG. 1,the central fluid conduit 44 is in fluid communication with and attachedon opposite ends to the control valve assembly 32 and the supply valveassembly 34. The central fluid conduit 44 is utilized to allowpressurized air to be communicated between the control valve assembly 32and the supply valve assembly 34. For example, in the embodimentillustrated in FIG. 1, when the control valve assembly 32 is energizedand/or in the second position and the supply valve assembly 34 isde-energized and/or in the first position, the source of pressurized air52 is in fluid communication with the first fluid conduit 42 via thecontrol valve assembly 32, central fluid conduit 44, and supply valveassembly 34. When in the second position, the control valve assembly 32is utilized to communicate the bleed of air to the supply valve assembly34, the first fluid conduit 42 and/or one or more fluid control circuits64, 66. Alternatively, the central fluid conduit 44 can be configured topermit pressurized air to be directed to the control valve assembly 32.For example, when the control valve assembly 32 and the supply valveassembly 34 are both de-energized and/or in their respective firstpositions, pressurized air in the first fluid conduit 42 can becommunicated from the supply valve assembly 34 to the control valveassembly 32 via the central fluid conduit 44. In other embodiments, likethe one illustrated in FIG. 2, the first fluid conduit 42 is attached toand directly in fluid communication with the control valve assembly 32.

In the embodiments illustrated in FIGS. 1 and 2, when the control valveassembly 32 is de-energized and/or in the first position, the controlvalve assembly 32 prohibits fluid communication between the source ofpressurized air 52 and a fluid control circuit 64, 66. However, when thecontrol valve assembly is de-energized and/or in the first position, thecontrol valve assembly 32 permits fluid communication between one ormore fluid control circuits 64, 66 and the atmosphere. Preferably, whenthe control valve assembly 32 is de-energized and/or in the firstposition, the first fluid conduit 42 is in fluid communication with achamber 70 provided in the control unit housing 14. When the first fluidconduit 42 is in fluid communication with the chamber 70 and ifpressurized air is within the first fluid conduit 42, the pressurizedair is directed to the chamber 70. Pressurized air may be directed tothe chamber 70 when the tire pressure management system 10, 10A is beingvented or when decreasing the tire pressure of one or more wheelassemblies 68, 68A, 68B, 68C. In the embodiment illustrated in FIG. 1,the first fluid conduit 42 is vented by directing pressurized air fromthe first fluid conduit 42 through the supply valve assembly 34, centralfluid conduit 44, control valve assembly 32, deflate conduit 72 anddeflate member 74 into the chamber 70 or directly to atmosphere.Similarly, when decreasing the tire pressure utilizing the tire pressuremanagement system 10 illustrated in FIG. 1, pressurized air from one ormore wheel assemblies 68, 68A, 68B, 68C is directed to the first fluidconduit 42 and, from the first fluid conduit 42, the pressurized air isdirected through the supply valve assembly 34, central fluid conduit 44,control valve assembly 32, deflate conduit 72 and deflate member 74 intothe chamber 70 or directly to atmosphere. In the embodiment illustratedin FIG. 2, the first fluid conduit 42 is vented by directing pressurizedair from the first fluid conduit 42 through the control valve assembly32, deflate conduit 72 and deflate member 74 into the chamber 70 ordirectly to atmosphere. Also, when decreasing the tire pressureutilizing the tire pressure management system 10A illustrated in FIG. 2,pressurized air from one or more wheel assemblies 68, 68A, 68B, 68C isdirected to the first fluid conduit 42 and, from the first fluid conduit42, the pressurized air is directed through the control valve assembly32, deflate conduit 72 and deflate member 74 into the chamber 70 ordirectly to atmosphere.

The first fluid conduit 42 is attached to and directly in fluidcommunication with the supply valve assembly 34. Preferably, when thesupply valve assembly 34 is energized and/or in the second position, thesource of pressurized air 52 is in fluid communication with the firstfluid conduit 42. Under these conditions, the supply valve assembly 34is utilized to communicate a flow of pressurized air from the source ofpressurized air 52 to the first fluid conduit 42. Thus, the supply valveassembly 34 may be utilized to promote air flow from the source ofpressurized air 52 to the first fluid conduit 42. When de-energizedand/or in the first position, the supply valve assembly 34 prohibits airflow from the source of pressurized air 52 to the first fluid conduit42. Under these conditions and in an embodiment like the one illustratedin FIG. 1, the supply valve assembly 34 may be utilized to communicate aflow of pressurized air from the first fluid conduit 42 to the controlvalve assembly 32 or from the control valve assembly 32 to the firstfluid conduit 42.

As noted above for the embodiment illustrated in FIG. 1, when the supplyvalve assembly 34 is de-energized and/or in the first position, thecontrol valve assembly 32 and the supply valve assembly 34 are in fluidcommunication via the central fluid conduit 44. Also, as noted above,when the control valve assembly 32 and the supply valve assembly 34 areboth de-energized and/or in their respective first positions and ifpressurized air is in the first fluid conduit 42, the supply valveassembly 34 allows pressurized air to be directed from the first fluidconduit 42 to the control valve assembly 32 via the central fluidconduit 44. Additionally, as should be appreciated, in this embodimentif the control valve assembly 32 and the supply valve assembly 34 areboth de-energized and/or in their respective first positions, the sourceof pressurized air 52 is not in fluid communication with the first fluidconduit 42.

The deflate conduit 72 is attached on an end the to the control valveassembly 32 and on an opposite end to the deflate member 74. Preferably,the deflate conduit 72 is provided within the housing 14. The deflateconduit 72 provides fluid communication between the control valveassembly 32 and the deflate member 74. The deflate conduit 72 directspressurized air from the control valve assembly 32 to the deflate member74. Thus, the deflate member 74 is in fluid communication with thecontrol valve assembly 32. As such, in embodiments where the controlvalve assembly 32 is de-energized and/or in the first position, thedeflate member 74 may be in fluid communication with the first fluidconduit 42.

The deflate member 74 is also in fluid communication with theatmosphere. Although the deflate member 74 is in fluid communicationwith the atmosphere, it is preferred that the deflate member 74 isprovided within the housing 14. The deflate member 74 is utilized todecrease the tire pressure of one or more wheel assemblies 68, 68A, 68B,68C. When tire pressure is being decreased, pressurized air from one ormore wheel assemblies 68, 68A, 68B, 68C passes through the deflatemember 74 to the atmosphere or to the atmosphere via the chamber 70 anda vent conduit 78.

The deflate member 74 comprises an opening 76. When tire pressure isbeing decreased, pressurized air from one or more wheel assemblies 68passes through the opening 76 before being released to the atmosphere.The opening 76 includes a cross-sectional area which is of a size thatcan be selected to allow for a desired decrease in tire pressure withina predetermined period of time. In certain embodiments, the size of thecross-sectional area can be selected to provide a desired backpressurein the tire pressure management system 10, 10A. The backpressureprovided is sufficient to maintain one or more wheel valves 62, 62A,62B, 62C in an open position when the tire pressure of one or more wheelassemblies 68, 68A, 68B, 68C is being decreased. Preferably, thebackpressure is provided in one or more of the fluid control circuits64, 66. More preferably, the deflate member 74 is configured so that thepressure provided to maintain one or more wheel valves 62, 62A, 62B, 62Cin an open position when a tire pressure is being decreased ispredetermined.

The size of the cross-sectional area of the opening 76 can be fixed.However, it is preferred that the size of the cross-sectional area ofthe opening 76 can vary. Preferably, the opening 76 has across-sectional area that is of a circular shape. However, in otherembodiments, the cross-sectional area of the opening 76 may be ofanother shape. When the size of the cross-sectional area is variable,the size of the cross-sectional area can increase or decrease tomaintain a desired flow of pressurized air through the opening 76. Inthis embodiment, a valve member may be provided as a portion of thedeflate member 74 and extend into and be movable within the opening 76to vary the size of the cross-sectional area. When the deflate member 74comprises a valve and the valve is within the opening 76, thecross-sectional area of the opening 76 may be of a ring shape. Varyingthe size of the cross-sectional area enables the flow of pressurized airthrough the opening 76 and the backpressure in the fluid control circuit64, 66 to be controlled and maintained.

The pressure sensor 26 is in fluid communication with the first fluidconduit 42. The pressure sensor 26 measures the pressure of the airwithin the first fluid conduit 42. When the source of pressurized air 52is in fluid communication with the first fluid conduit 42, the pressuresensor 26 can measure the pressure of the air from the source ofpressurized air 52 by measuring the pressure of the air in the firstfluid conduit 42. Also, during certain operations, the pressure sensor26 may measure the tire pressure by measuring the pressure of the air inthe first fluid conduit 42. Once the pressure of the air in the firstfluid conduit 42 has been measured, the pressure sensor 26 can send asignal to the electronic control portion 16.

As described above and illustrated in FIG. 1, the first fluid conduit 42is in fluid communication with the pressure sensor 26 and the supplyvalve assembly 34. Also, as described above, the first fluid conduit 42is selectively in fluid communication with the chamber 70 via thecontrol valve assembly 32. The first fluid conduit 42 is also attachedto and in fluid communication with one or more additional valveassemblies 36, 38.

As illustrated in FIG. 1, in certain embodiments, the pneumatic controlportion 18 comprises two channel valve assemblies 36, 38. In theseembodiments, a steer axle channel valve assembly 36 and a drive axlechannel valve assembly 38 are each attached to and in fluidcommunication with the first fluid conduit 42. Preferably, the steeraxle channel valve assembly 36 and drive axle channel valve assembly 38are of the solenoid variety. The steer axle channel valve assembly 36and the drive axle channel valve assembly 38 are operable from a firstposition through a second position and provided within the housing 14.Also, it is preferred that the channel valve assemblies 36, 38 are ofthe 3-way variety. In this embodiment, each channel valve assembly 36,38 is configured to permit fluid communication between the first fluidconduit 42 and a fluid control circuit 64, 66 or between a fluid controlcircuit 64, 66 and the atmosphere.

Preferably, the steer axle channel valve assembly 36 and the drive axlechannel valve assembly 38 are each normally in the first position.Preferably, when a channel valve assembly 36, 38 is de-energized, thevalve assembly 36, 38 is in the first position. Preferably, when achannel valve assembly 36, 38 is energized, the valve assembly 36, 38 isin the second position.

The steer axle channel valve assembly 36 is in fluid communication withone or more wheel valve assemblies 62, 62A via the first fluid controlcircuit 64. The steer axle channel valve assembly 36 separates the firstfluid conduit 42 from the first fluid control circuit 64. When the steeraxle channel valve assembly 36 is energized and/or in the secondposition, the first fluid conduit 42 is in fluid communication with thefirst fluid control circuit 64. Preferably, the first fluid controlcircuit 64 is selectively in fluid communication with one or more wheelassemblies 68, 68A provided on a steer axle (not depicted) of thevehicle. When the first fluid conduit 42 is in fluid communication withthe first fluid control circuit 64, a flow of air from the source ofpressurized air 52 can be directed to the wheel assemblies 68, 68Aprovided on the steer axle via the first fluid control circuit 64 andone or more wheel valves 62, 62A. Thus, the steer axle channel valveassembly 36 is utilized to promote air flow from the source ofpressurized air 52 to one or more wheel assemblies 68, 68A. When thesteer axle channel valve assembly 36 is de-energized and/or in the firstposition, the first fluid control circuit 64 is in fluid communicationwith the chamber 70. When the first fluid control circuit 64 is in fluidcommunication with the chamber 70 and if pressurized air is within thefirst fluid control circuit 64, venting the first fluid control circuit64 occurs. The first fluid control circuit 64 is vented by directing aflow of pressurized air from the first fluid control circuit 64 throughthe steer axle channel valve assembly 36 into the chamber 70.

When the drive axle channel valve assembly 38 is energized and/or in thesecond position, the first fluid conduit 42 is in fluid communicationwith the second fluid control circuit 66. Preferably, the second fluidcontrol circuit 66 is selectively in fluid communication with one ormore wheel assemblies 68B, 68C provided on a drive axle (not depicted)of the vehicle. When the first fluid conduit 42 is in fluidcommunication with the second fluid control circuit 66, a flow of airfrom the source of pressurized air can be directed to one or more wheelassemblies 68B, 68C provided on the drive axle via the second fluidcontrol circuit 66 and one or more wheel valves 62B, 62C. Thus, thedrive axle channel valve assembly 38 is utilized to promote air flowfrom the source of pressurized air 52 to one or more wheel assemblies68B, 68C. When the drive axle channel valve assembly 38 is de-energizedand/or in the first position, the second fluid control circuit 66 is influid communication with the chamber 70. When the second fluid controlcircuit 66 is in fluid communication with the chamber 70 and ifpressurized air is within the second fluid control circuit 66, ventingthe second fluid control circuit 66 occurs. The second fluid controlcircuit 66 is vented by directing a flow of pressurized air from thesecond fluid control circuit 66 through the drive axle channel valveassembly 38 into the chamber 70.

The first fluid control circuit 64 and the second fluid control circuit66 are similarly configured. Thus, only certain members of the firstfluid control circuit 64 will be described in more detail below. Itshould be appreciated that as the first fluid control circuit 64 and thesecond fluid control circuit 66 are similarly configured, the tirepressure management system 10, 10A can utilize the fluid controlcircuits 64, 66 in similar fashions. For example, as described above,each fluid control circuit 64, 66 can be utilized to provide fluidcommunication between one or more wheel assemblies 68, 68A, 68B, 68C andportions of the control unit 12. Also, as described above, both thefirst fluid control circuit 64 and the second fluid control circuit 66may be vented, either separately or simultaneously. Thus, certainoperations of the tire pressure management system 10, 10A will only bedescribed with respect to the first fluid control circuit 64. It shouldbe appreciated that the tire pressure management system 10, 10A is notlimited to utilizing only the first fluid control circuit 64 asdescribed below in performing one or more of the operations describedherein.

The first fluid control circuit 64 comprises a fluid conduit 80 and thechannel port 48. The fluid conduit 80 is preferably provided in thehousing 14 and is attached to and in fluid communication with the steeraxle channel valve assembly 36 on an end. On another end, the fluidconduit 80 is attached to and in fluid communication with the channelport 48. The fluid control circuit 64 may also comprise one or moreadditional fluid conduits 82, a rotary seal assembly 84 and/or a hoseassembly (not depicted).

The first fluid control circuit 64 is in fluid communication with one ormore wheel valves 62, 62A. Preferably, each wheel valve 62, 62A issimilarly configured and operates in a similar fashion. As such, theconfiguration and operation of only one wheel valve 62 will be describedbelow.

The wheel valve 62 is attached to and in fluid communication with thewheel assembly 68. Preferably, the wheel valve 62 is a control valve.More preferably, the wheel valve is a bi-directional control valve. Asshould be appreciated, the term bi-directional control valve means thatpressurized air flows to the wheel assembly 68 through the wheel valve62 when the tire pressure is being increased and flows from the wheelassembly 68 through the wheel valve 62 when the tire pressure is beingdecreased.

In an embodiment, the wheel valve 62 is as described in WO 2014/028142A1, the entire disclosure of which is hereby incorporated by reference.In another embodiment, the wheel valve 62 is as described in U.S.provisional patent application No. 62/281,896, the entire disclosure ofwhich is hereby incorporated by reference. The wheel valve 62 separatesthe fluid control circuit 64 from the wheel assembly 68 and is utilizedto retain pressurized air therein. Also, the wheel valve 62 allows thewheel assembly 68 to selectively communicate with the control unit 12and portions thereof via the first fluid control circuit 64. The wheelvalve 62 is operable from an open position to a closed position. In anopen position, pressurized air flows to the wheel assembly 68 throughthe wheel valve 62 when the tire pressure is being increased and flowsfrom the wheel assembly 68 through the wheel valve 62 when the tirepressure is being decreased. Thus, in an open position, the wheel valve62 permits the tire pressure to be measured, increased, or decreased. Inthe closed position, the wheel valve 62 prohibits pressurized air frombeing removed from or being added to the wheel assembly 68.

The pressurized air housed within the wheel assembly 68 is referred toherein as “tire pressure.” Tire pressure is increased by addingpressurized air into the wheel assembly 68 and decreased by removing airfrom the wheel assembly 68. Preferably, the tire pressure is equal to atarget tire pressure. The target tire pressure can be selected by anoperator of the vehicle to be a desired pressure. After the target tirepressure is selected, it can be programmed into the control unit 12 viathe electronic control portion 16. The target tire pressure can also bepre-programmed into the control unit 12. To ascertain if the tirepressure is equal to the target tire pressure, the tire pressure ismeasured. As noted above, the control unit 12 is configured to enablemeasuring the tire pressure.

If it is determined that the tire pressure is less than the target tirepressure, the tire pressure can be increased. If it is determined thatthe tire pressure is greater than the target tire pressure, the tirepressure can be decreased. After the tire pressure has been increasedand/or decreased, the tire pressure can be measured again as needed.Also, if the tire pressure is equal to the target tire pressure, thetire pressure can be measured again at a later time.

As noted above, the tire pressure is increased by adding pressurized airinto the wheel assembly 68, 68A, 68B, 68C. The tire pressure of aplurality of wheel assemblies 68, 68A, 68B, 68C can be increased to thetarget tire pressure. Also, it should be appreciated that the tirepressure can be increased for the wheel assemblies 68, 68A, 68B, 68C ofthe steer axle or drive axle. However, due to differences in thepreferred target tire pressures of the wheel assemblies 68, 68A, 68B,68C of the steer axle and drive axle, it is preferred that the tirepressures of the wheel assemblies 68, 68A, 68B, 68C of theaforementioned axles be increased separately.

When the tire pressure is to be measured, increased, or decreased, thewheel valve 62 is urged to an open position. It should be appreciatedthat the wheel valve 62 may be urged to an open position utilizing avariety of methods. Preferably, the wheel valve 62 is urged to an openposition utilizing one or more pulses of pressurized air. In certainembodiments, the supply valve assembly 34 is energized and de-energizedone or more times in a predetermined period of time to provide one ormore pulses of air to open the wheel valve 62. As should be appreciated,energizing the supply valve assembly 34 places the valve assembly intothe second position and permits fluid communication between the airsupply conduit 40 and the first fluid control circuit 64. It should alsobe appreciated that in the embodiments illustrated, the steer axlechannel valve assembly 36 is also energized and/or in the secondposition to permit fluid communication between the air supply conduit 40and the first fluid control circuit 64. The control valve assembly 32 isenergized and/or in the second position when the one or more pulses ofpressurized air are being provided. In these embodiments, each pulse ofair may be provided for a predetermined period of time. Thepredetermined period of time that each pulse of air is provided for maybe of the same duration. Alternatively, each pulse of air may beprovided for a predetermined period of time that is of a longer durationor a shorter duration than the predetermined period of time for aprevious or subsequent pulse of air. Once the wheel valve 62 is open,the tire pressure can be measured utilizing the pressure sensor 26. Thewheel valve 62 may also be urged to the closed position when desiredsuch as, for example, when the tire pressure has been increased to thetarget tire pressure.

Once the wheel valve 62 is in the open position, the tire pressure canbe increased by any number of methods. For example, the tire pressurecan be increased by utilizing one or more pulses of pressurized air toadd pressurized air to the wheel assembly 68. A pulse of air can beprovided as described above utilizing one or more pulses of pressurizedair to increase the tire pressure helps to prevent over-inflation of thewheel assembly 68.

Once open, the wheel valve 62 can be maintained in the open position forone or more predetermined periods of time to increase the tire pressureto the target tire pressure. The wheel valve 62 can be maintained in theopen position utilizing the bleed air. After the tire pressure has beenincreased to the target tire pressure, the wheel valve 62 is urged tothe closed position when the channel valve assembly 36 is moved to thefirst position and/or de-energized.

Alternatively, once the wheel valve 62 is in the open position, the tirepressure can be decreased. Decreasing the tire pressure will bedescribed primarily with reference to the tire pressure of one wheelassembly 68. However, the method is suitable for use in decreasing thetire pressure of one or more wheel assemblies simultaneously.Additionally, the method of decreasing tire pressure will be describedfor use with the first fluid control circuit 64. However, it should beappreciated that the method can be utilized with the second fluidcontrol circuit 66.

When decreasing the tire pressure, the control valve assembly 32 and thesupply valve assembly 34 are de-energized and/or moved to theirrespective first positions. In the embodiment illustrated in FIG. 1 andin the condition mentioned above, the valve assemblies 32, 34 are influid communication with each other via the central fluid conduit 44.Also, when the tire pressure is being decreased, the steer axle channelvalve assembly 36 is energized and/or in the second position. With thewheel valve 62 in the open position and the valve assemblies 32, 34, 36as described, a stream of pressurized air is directed from the wheelassembly 68 through the wheel valve 62, fluid control circuit 64, steeraxle channel valve assembly 36, first fluid conduit 42, supply valveassembly 34, central fluid conduit 44, control valve assembly 32 and thedeflate conduit 72 to the deflate member 74. Alternatively, asillustrated in the embodiment depicted in FIG. 2, the stream ofpressurized air is directed from the wheel assembly 68 through the wheelvalve 62, fluid control circuit 64, steer axle channel valve assembly36, first fluid conduit 42, control valve assembly 32 and the deflateconduit 72 to the deflate member 74. From the deflate member 74, thestream of pressurized air is directed directly to the atmosphere or thechamber 70 to decrease the tire pressure. Thus, when the tire pressureis being decreased, the deflate member 74 is in fluid communication withthe wheel valve 62 via the fluid control circuit 64. Under theconditions described above, the deflate member 74 is in fluidcommunication with the fluid control circuit 64 if the steer axlechannel valve assembly 36 is energized and/or in the second position.

The flow of pressurized air from the wheel assembly 68 through deflatemember 74 can be controlled so that if a particular backpressure isrequired in the fluid control circuit 64 to maintain the wheel valve 62in the open position, then the backpressure required can be provided.The wheel valve 62 can be maintained in the open position as the tirepressure is decreased. As pressurized air is being removed from thewheel assembly 68, the pressure sensor 26 can measure a pressure of theair in the first fluid conduit 42 and provide a signal which correspondsto the tire pressure. If the tire pressure measured by the pressuresensor 26 is greater than the target tire pressure, the tire pressurecan be decreased until the tire pressure is equal to the target tirepressure.

In an embodiment, the method comprises decreasing a plurality of tirepressures simultaneously. In this embodiment, the tire pressures may beequalized before being decreased simultaneously. Preferably, the tirepressures are equalized by decreasing the tire pressure of the wheelassembly having the highest tire pressure so that the tire pressure isequal to or about equal to the tire pressure of the wheel assemblyhaving the lowest tire pressure. The step of decreasing the tirepressure of the wheel assembly having the highest tire pressure to beequal to or about equal to the tire pressure of the wheel assemblyhaving the lowest tire pressure can be repeated as required until thetire pressures of the wheel assemblies are equal to each other. Once thetire pressures to be decreased are equal or about equal, the tirepressures can be decreased by opening the appropriate wheel valvessimultaneously as described above and directing streams of air from thewheel assemblies 68 to the deflate member 74.

If the pressure sensor 26 measures a pressure in the first fluid conduit42 indicative of the tire pressure which is equal to the target tirepressure, decreasing the tire pressure is completed. Once decreasing thetire pressure is complete, the steer axle channel valve assembly 36 isde-energized and/or placed in the first position. As described above,placing the steer axle channel valve assembly 36 in the first positionand/or de-energizing the valve assembly 36 urges the wheel valve 62 tothe closed position. With the wheel valve 62 in the closed position,further decreases in tire pressure are prevented as additional air isprevented from being removed from the wheel assembly 68.

In certain embodiments, the tire pressure is measured and is determinedto be equal to the target tire pressure. Once the tire pressure is equalto the target tire pressure, increasing or decreasing the tire pressureis not desired. In these embodiments, the system 10, 10A may be vented.Preferably, the tire pressure management system 10, 10A is vented byremoving pressurized air one or more portions of the system. Forexample, it is preferably that any pressurized air within the firstfluid conduit 42, the first fluid control circuit 64 and the secondfluid control circuit 66 is removed once the tire pressure is equal tothe target tire pressure. Additionally, the system 10, 10A may be ventedif communication or power is lost to the system 10, 10A.

As described above, pressurized air from the first fluid conduit 42, thefirst fluid control circuit 64 and/or the second fluid control circuit66 can be directed to the chamber 70 via the control valve assembly 32,steer axle channel valve assembly 36 and drive axle channel valveassembly 38, respectively. When it is desired to vent the tire pressuremanagement system 10, 10A, the control valve assembly 32, supply valveassembly 34, steer axle channel valve assembly 36 and drive axle channelvalve assembly 38 are in or placed in their respective first positionsby de-energizing the valve assemblies 32, 34, 36, 38. When theaforementioned valve assemblies 32, 34, 36, 38 are de-energized, ventingthe first fluid conduit 42, the first fluid control circuit 64 and thesecond fluid control circuit 66 is enabled. If pressurized air is withinthe first fluid conduit 42, the first fluid control circuit 64 and thesecond fluid control circuit 66, the pressurized air is directed to thechamber 70 via the control valve assembly 32, steer axle channel valveassembly 36 and drive axle channel valve assembly 38, respectively.Preferably, pressurized air from the first fluid control circuit 64 andthe second fluid control circuit 66 is directed into chamber 70 from thesteer axle channel valve assembly 36 and drive axle channel valveassembly 38 from an opening 86 provided in each valve assembly 36, 38.Pressurized air from the first fluid conduit 42 is directed into chamber70 from the control valve assembly 32 via the deflate member 74. Asillustrated in the embodiment shown in FIG. 1, prior to being directedinto the chamber 70 from the control valve assembly 32, the pressurizedair may be directed to the control valve assembly 32 via the centralfluid conduit 44 and supply valve assembly 34.

As noted above, the chamber 70 is provided within the housing 14 and maybe in fluid communication with the atmosphere via the vent conduit 78.When provided, the vent conduit 78 extends from the chamber 70 to anouter surface of the housing 14. After pressurized air is received fromthe first fluid conduit 42, the first fluid control circuit 64 and/orthe second fluid control circuit 66, the vent conduit 78 directs thepressurized air in the chamber 70 to the atmosphere. Preferably, thevent conduit 78 is formed in the lower portion 22 of the housing 14 andextends in a downward direction. Forming the passage 66 in the lowerportion 22 of the housing 14 and to extend in a downward direction helpsto prevent dirt and debris from entering the housing 14.

In certain embodiments, a valve 88 may be positioned in the vent conduit78. Preferably, the valve 88 is of the check valve variety. The valve 88may be formed of rubber or another elastomeric material. In theseembodiments, the valve 88 allows pressurized air in the chamber 70 to bedischarged to the atmosphere and prevents air from the atmosphere fromentering the chamber via the vent conduit 78. Thus, the valve 88 helpsto prevent dirt and debris from entering the housing 14 via the ventconduit 78. To determine when venting of the aforementioned portions ofthe tire pressure management system 10, 10A has been completed, thepressure sensor 26 measures the pressure of the air in the first fluidconduit 42.

From the foregoing detailed description, it will be apparent thatvarious modifications, additions, and other alternative embodiments arepossible without departing from the true scope and spirit. Theembodiments discussed herein were chosen and described to provide thebest illustration of the principles of the invention and its practicalapplication to thereby enable one of ordinary skill in the art to usethe invention in various embodiments and with various modifications asare suited to the particular use contemplated. As should be appreciated,all such modifications and variations are within the scope of theinvention.

The invention claimed is:
 1. A tire pressure management system,comprising: a wheel valve in fluid communication with a wheel assembly;a supply valve assembly selectively in fluid communication with thewheel valve through a fluid control circuit, the supply valve assemblypermitting fluid communication between a source of pressurized air andthe fluid control circuit; and a control valve assembly selectively influid communication with the wheel valve through the fluid controlcircuit, the control valve assembly permitting fluid communicationbetween the source of pressurized air and the fluid control circuit orbetween the fluid control circuit and atmosphere.
 2. The tire pressuremanagement system of claim 1, further comprising a deflate member influid communication with the control valve assembly through a deflateconduit.
 3. The tire pressure management system of claim 1, furthercomprising a channel valve assembly which is in fluid communication withthe wheel valve through the fluid control circuit and separates thefluid control circuit from a first fluid conduit.
 4. The tire pressuremanagement system of claim 1, further comprising a central fluid conduitin fluid communication with the supply valve assembly on an end and thecontrol valve assembly on another end, the central fluid conduit beingconfigured to permit pressurized air to be directed to the control valveassembly when the supply valve assembly is de-energized.
 5. The tirepressure management system of claim 2, wherein the deflate member is influid communication with the wheel valve when the control valve assemblyand the supply valve assembly are both de-energized and a channel valveassembly is energized.
 6. The tire pressure management system of claim2, wherein the deflate member is in fluid communication with a firstfluid conduit when the control valve assembly is de-energized.
 7. Thetire pressure management system of claim 2, wherein the deflate membercomprises an opening which has a cross-sectional area.
 8. The tirepressure management system of claim 2, wherein the deflate member is influid communication with atmosphere and configured so that apredetermined pressure is provided in the fluid control circuit, whereinthe predetermined pressure is sufficient to maintain the wheel valve inan open position.
 9. The tire pressure management system of claim 2,wherein the supply valve assembly, control valve assembly, deflateconduit and deflate member are provided within a housing and the deflatemember is in fluid communication with atmosphere through a chamberprovided within the housing.
 10. The tire pressure management system ofclaim 3, wherein the first fluid conduit is attached to and in fluidcommunication with the supply valve assembly.
 11. The tire pressuremanagement system of claim 3, wherein the channel valve assembly permitsfluid communication between the fluid control circuit and the firstfluid conduit or between the fluid control circuit and atmosphere. 12.The tire pressure management system of claim 3, further comprising apressure sensor in fluid communication with the first fluid conduit. 13.The tire pressure management system of claim 6, wherein the deflatemember is in fluid communication with the wheel valve through the fluidcontrol circuit when a channel valve assembly is energized.
 14. The tirepressure management system of claim 7, wherein the deflate membercomprises a valve which is moveable within the opening to control theflow of pressurized air therethrough.
 15. The tire pressure managementsystem of claim 7, wherein the cross-sectional area of the openingvaries in size to maintain a predetermined pressure in the fluid controlcircuit, wherein the predetermined pressure is sufficient to maintainthe wheel valve in an open position when the tire pressure is beingdecreased.
 16. The tire pressure management system of claim 10, whereinthe first fluid conduit is attached to and in fluid communication withthe control valve assembly.
 17. The tire pressure management system ofclaim 14, wherein when the valve is disposed within the opening.
 18. Amethod for decreasing tire pressure, comprising: providing a wheelassembly that houses pressurized air; providing a wheel valve that is influid communication with the wheel assembly, the wheel valve beingoperable from an open position to a closed position; providing a supplyvalve assembly which is selectively in fluid communication with thewheel valve through a fluid control circuit; providing a control valveassembly which is selectively in fluid communication with the wheelvalve through the fluid control circuit; providing a deflate memberwhich is in fluid communication with the control valve assembly andselectively in fluid communication with the wheel valve; and selecting atarget tire pressure; wherein if a pressure of the pressurized air inthe wheel assembly is greater than the target tire pressure, thendecreasing the pressure of the pressurized air in the wheel assembly bydirecting a flow of pressurized air from the wheel assembly through thewheel valve, control valve assembly, and deflate member.
 19. The methodfor decreasing tire pressure of claim 18, further comprising providing achannel valve assembly which is in fluid communication with the wheelvalve through the fluid control circuit, the channel valve assemblypermitting fluid communication between the fluid control circuit and afirst fluid conduit or between the fluid control circuit and atmosphere,wherein the flow of pressurized air is directed to the deflate memberwhen the control valve assembly is de-energized and channel valveassembly is energized.
 20. The method for decreasing tire pressure ofclaim 19, further comprising de-energizing the supply valve assembly.